1. Field of the Invention
The present invention relates to a rotary cutter for a mower used for mowing grass, lawn, and the like with a cord (principally made of nylon) extending in a radial direction of a case which is rotationally-driven by power of a motor or the like by way of an axis of rotation.
2. Description of the Related Art
As this type of rotary cutter, it is conventionally known a rotary cutter having a reel which houses a nylon cord, wherein when the cord is worn away, the cord is let out from the reel by pressing the cutter on the ground during rotation, by tapping the cutter or by running up the rotation of the cutter. As to this type of rotary cutter, when the cord housed in the reel was worn out, it was necessary to take out the reel by disassembling the rotary cutter, and wind a new cord, and then rearranging its components again. However, by such a way, it is very troublesome and inconvenient to carry out such procedures during mowing. Moreover, when the rotary cutter is disassembled and the reel is taken out, it has been feared that these components may be lost since associated components of the reel and other components are taken out at the same time. On this account, as the rotary cutter in which a cord replacement can be simplified when the cord is worn away, or, the rotary cutter in which the cord is replaceable without disassembling the rotary cutter itself, for example, a rotary cutter in which through-holes are formed in a part of a cylindrical body (a cord-winding part) of a reel, and the cord is inserted through the through-holes and wound onto the cylindrical body of the reel, is suggested (see Patent Documents 1 to 3).    Patent Document 1: Utility model registration No. 2,509,199    Patent Document 2: Japanese Patent Laid-Open No. 2005-124501    Patent Document 3: Published Japanese Translation of a PCT Application 2006-514837
In the case of the conventional rotary cutter as claimed in Patent documents 1 to 3, there is an advantage that the cord is replaceable without disassembling the rotary cutter and taking out the reel. However, for example, in the case of a rotary cutter described in Patent document 1, there are some drawbacks that it is necessary to provide a cord through-hole formed between an outer circumferential surface and an inner circumferential surface of a cylindrical body of a reel (a cord-winding part) of a reel, the cord through-hole being perpendicular to an axis of rotation without providing on the inner circumferential surface, so that top and bottom positions of its cord insertion opening and a guiding hole can be on the same horizontal plane. As a result, production/processing cannot be easily carried out in order to form its cord through-hole and the guiding hole. Therefore, the production cost of such a rotary cutter can be relatively high. Moreover, a rotary cutter described in Patent document 2 has a structure that a cord is sorted into upper and lower of two layers of a reel and is wound on the reel, and cord insertion holes are formed to sort the cord into up and down at a part of its partition. Therefore, such a rotary cutter has some drawbacks that the structure of the reel is relatively complicated; a lot of time and effort are needed for its production/processing; and the production cost of such a rotary cutter can be relatively high. In the case of the rotary cutter described in Patent document 3, the rotary cutter is comprised of two components of a cylindrical securement head having a reel at its shaft core, and a spool (a cord-winding part) mounted to the securement head. The spool, which is similar to that of the rotary cutter described in Patent document 2, has a structure that a cord is sorted into up and down and is wound thereon, and cord insertion holes are formed to sort the cord into up and down at a part of its partition through the spool and the securement head.
Therefore, the rotary cutter of Patent document 3 has some drawbacks that the structure of the reel is more complicated; much more time and effort are needed for its production/processing; and the production cost of such a rotary cutter can be higher. Further, in the case of the conventional rotary cutter as claimed in Patent documents 1-3, there is a common drawback that the insertion/conduction operation of the cord when the cord is wound on the reel requires time and effort.
The object of the present invention is to overcome the drawbacks of the above-described conventional rotary cutter, and to realize a rotary cutter in which its production/processing is simple and the production cost is inexpensive, having no possibility of losing associated components of a reel and other components when replacing a cord, and allowing the cord to be easily and quickly wound up.